Here's a simple project to add some cheap (free) Valentine's decorations around the house. I used an old pickle jar, mod podge, glitter, and a piece of sticky back paper (contact paper, or even heart shaped stickers).
Press the heart onto the glass. Mix the glitter with the mod podge (about 1/4 cup mod podge and a tablespoon plus of glitter-the more you use, the thicker the wall). Roll it around the jar until it's all covered. Let it dry for about 2 hours and carefully peel the sticker off before it dries completely (or it will create a film over the back of the heart and be more difficult to peel off cleanly later. It will look white for a day, but the mod podge will dry clear without about 2 days.